docs: def has_submenu_items(self, current_page, allow_repeating_parents,
                            original_menu_tag, menu_instance=None, request=None):
          """
          When rendering pages in a menu template a `has_children_in_menu`
          attribute is added to each page, letting template developers know
          whether or not the item has a submenu that must be rendered.
  
          By default, we return a boolean indicating whether the page has
          suitable child pages to include in such a menu. But, if you are
          overriding the `modify_submenu_items` method to programatically add
          items that aren't child pages, you'll likely need to alter this method
          too, so the template knows there are sub items to be rendered.
          """
          return menu_instance.page_has_children(self)